Automatic emergency furnace control



8, 1957 c. w. STOCKWELL 2,777,074

AUTOMATIC EMERGENCY FURNACE CONTROL Filed Jan. 1953 FIG. I l6 INVENTOR MMW United States Patent 2,777,074 AUTOMATIC EMERGENCY FURNACE CONTROL Charles W. Stockwell, Mansfield, Ohio Application January 8, 1953, Serial No. 330,186 1 Claim. (Cl. 307-64) This invention relates to an automatic emergency furnace control.

It is an object of the present invention to provide an automatic furnace control adapted to keep the furnace supplied with electricity should the power lines be broken and there be a resultant failure of power.

it is another object of the invention to provide an automatic emergency furnace control unit which can be easily installed upon the furnace and connected with the power line source and wherein upon failure of the electric current, the contact arm would be released to make contact with one of the electrical source wires and deliver battery voltage to the furnace and wherein the contact arm is normally retained by a relay to close the secondary circuit from the transformer but upon failure of power source, the relay releases the contact arm so that the current is delivered to the furnace leads by the battery.

It is another object of the invention to provide an automatic emergency furnace control which will keep the furnace in operation even though the electric power fails in the power lines, which is of simple construction, easy to install on the furnace, inexpensive to manufacture, has a minimum number of parts, compact, automatic and efiicient in operation.

For other objects and for a better understanding of the invention, reference may be had to the following detailed description taken in connection with the accompanying drawing, in which:

Figure l is a perspective view of the unit including the battery and the relay and embodying the features of the present invention;

Fig. 2 is wiring diagram of the electrical circuit.

Referring now to the figures, represents a supporting plate having a bracket 11 for supporting a battery 12. This battery has a negative terminal 13 which is connected to a cable 14 and a connector 15 to a furnace lead wire 16 that extends from transformer 17 having a secondary winding 18 and a primary winding 19. The wire 16 is connected to one side of the secondary winding 18. The other side of the secondary winding 18 is connected to a cable 20 with a contact 21 of a relay 22. Adjacent the contact 21 is a contact 23 which can be bridged by contact arm 24 with contact 21 whereby to close through cable 25 leading to a contact 26 the secondary of the transformer circuit which has a cable 27 that leads to the furnace leads and can be connected to one of the same by a connector 28.

The relay 22 has a magnet coil 29 that is supplied by the regular 115 volt power supply by a cable 30 having wires 31 and 32 that connected respectively with coil terminals 33 and 34. The cable 30 has a plug 35, adapted to fit a wall receptacle.

The contact arm 24 is carried on a magnetizable member 37 hinged at 38 to relay frame 39. A tension spring 41 is connected to a projection 42 on the frame 39 and to one end of the hinged member 37. The spring 41 urges the hinge member to a position so that the contact arm 24 is down and in engagement with contact 26. When the power supply is available, the coil 29 is energized and the member 37 will draw toward the coil 29 against the action of the spring 41 and the contact 24 will bridge the contacts 21 and 23 so that electric current is Patented Jan. 8, 1957 supplied to the furnace leads through the wire or cable 27. This supply of current to the furnace leads continues as long as the relay is energized, but upon failure of the current supply, the tension spring 41 will move the member 37 outwardly so that the contact arm 24 will engage contact 26. The battery 12 has its positive terminal 43 connected by a wire 44 with contact arm 24, as indicated at 45.

When the contact arm 24 is against the contact 26, the furnace leads will be supplied with current from the battery 12. The battery or circuit is connected to the lead Wire 16 and the contact arm 24 will be connected to the contact 26 and the lead wire 27, the circuit including the battery 12, wire 14, wire 44, terminal 45, contact arm 24, and contact 26. This battery will keep the furnace in operation if the power fails. When the power is restored, the coil 29 of the relay 22 will again be energized, and contact 24 will be moved to bridge the contacts 21 and 23 so that the furnace leads will again be supplied from the secondary winding 18 of the transformer 17.

It is to be understood that provision is made for disconnecting lead 44 in Fig. 2 from arm 24 when solenoid 29 is energized and when, therefore, arm 24 connects contacts 21 and 23. For instance, suitable contacts may be associated with the relay 22, such contacts being disconnected when relay 22 is energized and such contacts being connected when relay 22 is de-energized, such contacts to be inserted in series with lead 44 of Fig. 2. Details such as the foregoing are within the province of a man skilled in the art, and therefore no illustration of any such provision has been thought necessary in the drawings.

It should now be apparent that there has been provided an automatic emergency furnace control for gas and oil furnaces whereby auxiliary battery power is supplied upon failure of the regular alternating current supply.

While various changes may be made in the detail construction, it shall be understood that such changes shall be within the spirit and scope of the present invention, as defined by the appended claim:

What is claimed is:

An automatic emergency gas furnace control comprising a transformer having an input coil adapted to be connected to a primary source of power, and an output coil with two terminals, 2. first gas furnace lead connected to one terminal of the output coil, a second gas furnace lead,

I a relay having a first contact conecte'd in the circuit of said second gas furnace lead, said relay including an electromagnet adapted to be connected to the primary source of power, a second contact on said relay and a wire bridging the first contact with the second contact, a third contact on said relay and connected to the other terminal of the output coil, said relay further including a movable contact arm adapted to bridge the second and third contacts when the said coil is energized, spring means for normally retaining said contact arm away from said electromagnet and in engagement with the first contact, an auxiliary source of power, one terminal of said auxiliary source of power being connected to said first furnace lead, the other terminal of said auxiliary source of power being connected to said relay movable contact arm, whereby to place said auxiliary source of power between the furnace leads automatically upon failure of the primary source of power.

References Cited in the file of this patent UNITED STATES PATENTS 948,758 Denmeen Feb. 8, 1910 1,284,977 Averill Nov. 19, 1918 2,070,740 Larson Feb. 16, 1937 2,105,599 Hyde Jan. 18, 1938 2,476,517 Titus July 19, 1949 

